Field of the Invention
[0001] The invention relates to mobile communications in general and in particular to methods
and devices for providing a secure element, such as a subscriber identity module (SIM),
an eUICC/UICC or the like, of a mobile terminal with a subscription profile for communicating
via a mobile network.
Background of the Invention
[0002] Communicating by means of a mobile terminal, such as a mobile phone, via a public
land mobile network (PLMN; also referred to as a mobile or cellular network herein)
operated by a mobile network operator (MNO) generally requires the mobile terminal
to be equipped with a secure element for securely storing data uniquely identifying
the user of the mobile terminal (also called subscriber). For instance, in the context
of a mobile terminal configured to communicate according to the Global System for
Mobile Communications (GSM), currently the world's most popular standard for mobile
communications systems, the secure element is called a subscriber identity module
(SIM) and is usually provided in the form of a smart card. According to the GSM standard,
the technical features of which are defined by a large number of interrelated and
mutually dependent specifications published by the ETSI standardization organization,
the SIM contains subscription credentials for authenticating and identifying the user
of the mobile terminal, including in particular an International Mobile Subscriber
Identity (IMSI) and an authentication key K
i. These subscription credentials are generally stored on the SIM by the SIM manufacturer/vendor
or the MNO during a SIM personalization process prior to providing the user of the
mobile terminal with his SIM. A non-personalized SIM is generally not suited for use
in a mobile terminal, i.e. the use of the services provided by a PLMN with a non-personalized
SIM without the necessary subscription credentials is not possible.
[0003] One particular field of application of secure elements, such as SIMs, eUICCs, UICCs
and the like, which is expected to grow rapidly in the near future is M2M (machine-to-machine)
communication, i.e. the communication between machines over a mobile network without
human intervention, also called the Internet of things. In M2M communication data
is automatically transmitted between many different types of machines equipped with
a secure element in the form of a M2M module, such as TV systems, set top boxes, vending
machines, vehicles, traffic lights, surveillance cameras, sensor devices, metering
devices, and the like. It is foreseeable that at least for some of these devices it
will not be possible or at least very difficult to provide the secure element beforehand
with the necessary subscription credentials, including for instance an IMSI. This
is because in a lot of M2M devices the secure element will most likely be implemented
in the form of a surface mounted chip or an embedded chip module without the possibility
of providing the secure element with the necessary subscription credentials beforehand.
Consequently, once in the field, these M2M devices and their non-personalized secure
elements require the secure provisioning of subscription credentials over-the-air.
[0004] When using the services provided by a MNO, in particular communicating via the PLMN
provided by the MNO, the user of a mobile terminal is usually charged a certain monthly
fee by the MNO. If the mobile user wants, for instance due to a lower monthly charge
and/or superior services, to change to a different MNO, he generally has to manually
replace the SIM provided by the current MNO and containing, in particular, the subscription
credentials necessary for attaching to the PLMN of the current MNO by the SIM provided
by the new MNO and containing the subscription credentials necessary for attaching
to the PLMN of the new MNO. Certainly, it would be more convenient for the user, if
instead of this process of switching to a new MNO by manually replacing the SIM it
would be possible to use one and the same secure element in the form of a SIM that
can be "reprogrammed" over-the-air by downloading a corresponding subscription profile
including subscription credentials and automatically implementing the same on the
SIM.
[0005] Such methods for downloading a subscription profile and implementing the same on
a secure element are known. However, in practice, it will often be the case that a
subscription profile is provided by an entity, for instance, a mobile network operator
(MNO), different to the entity that originally manufactured the secure element, i.e.
the secure element manufacturer. As usually only the secure element manufacturer has
knowledge about the specific details of the secure element, such as its operating
system as well as any subscription management interfaces for implementing a new subscription
profile on the secure element, for instance in the form of a suitably configured application
programming interface (API), which, in particular, for security reasons, the secure
element manufacturer wants to keep secret, the problem can arise that the subscription
profile provided by an MNO is in a format that is not compatible with the subscription
management interface implemented on the secure elements.
[0006] There is, therefore, a need for improved methods and devices for providing a secure
element, such as a subscriber identity module (SIM), an eUICC/UICC or the like, of
a mobile terminal with a subscription profile for communicating via a mobile network,
wherein these methods and devices address the issues described above.
Summary of the Invention
[0007] The above need is addressed according to the present invention by the subject-matter
of the independent claims. Preferred embodiments of the invention are defined in the
dependent claims.
[0008] According to a first aspect of the invention there is provided a method for providing
a secure element having a processor and a memory of a mobile terminal with a target
subscription profile for communicating via a target mobile network. The method comprises
the steps of: providing as a first part of the target subscription profile a subscription
management interface to the secure element; implementing the subscription management
interface on the secure element; and providing as a second part of the target subscription
profile subscription data in a format defined by the operator of the target mobile
network to the secure element, wherein the subscription management interface allows
the secure element to process the subscription data (in the format used by the operator
of the target mobile network) and to implement the target subscription profile thereon
for allowing access to the target mobile network.
[0009] Preferably, the subscription management interface implements a standardized API on
the secure element for processing the subscription data used by the operator of the
target mobile network.
[0010] According to preferred embodiments of the invention, the method comprises prior to
the step of providing as a first part of the target subscription profile a subscription
management interface to the secure element the additional step of attaching to a mobile
network supported by a subscription profile already present on the secure element.
This subscription profile already present on the secure element could be a provisioning
subscription profile. Preferably, the method comprises prior to the step of providing
as a first part of the target subscription profile a subscription management interface
to the secure element the additional step of requesting the target subscription profile
from a subscription management backend system.
[0011] According to preferred embodiments of the invention, the method comprises after the
step of implementing the subscription management interface on the secure element the
additional step of sending a confirmation message to a subscription management backend
system. Preferably, the step of implementing the subscription management interface
on the secure element comprises the additional step of checking the integrity of the
subscription management interface.
[0012] Preferably, the method comprises after the step of providing the subscription data
in a format defined by the operator of the target mobile network to the secure element
the additional steps of attaching to the target mobile network and sending a confirmation
message to a subscription management backend system.
[0013] The present invention provides, amongst others, for the advantage that the entity
providing for the target subscription profile can continue using its proprietary subscription
management methods and formats, while the secure element manufacturer can continue
using its subscription management methods and formats without revealing any confidential
information.
[0014] As used herein, a "subscription profile" (or short "subscription") can comprise at
least parts of a secure element operating system, one or more applications, files
and/or data, such as subscription credentials. As used herein, the expression "providing
a secure element of a mobile terminal with a subscription profile" comprises the complete
exchange of an old subscription profile with a new subscription profile, the addition
of a new subscription profile besides an already existing subscription profile as
well as a partial exchange of an existing subscription profile which may be an update
of the existing subscription profile.
[0015] According to a second aspect the invention provides for a secure element comprising
a subscription profile provided to the secure element by the method according to the
first aspect of the invention.
[0016] Preferably, the secure element is a subscriber identity module (SIM) for authentication/identification
of a subscriber in the cellular communications network. Such a SIM communicates with
the mobile terminal via a card reader therein and can be removed in principle from
the mobile terminal to be either replaced by a different SIM and/ or used in a different
mobile terminal. Alternatively, the secure element is an integral part of the mobile
terminal such as a hard-wired chip module. Such embedded secure elements are known,
for instance, as embedded Universal Integrated Circuit Cards (eUICCs). Preferably,
the secure element supports storage of multiple subscription profiles which may be
associated with different MNOs. Generally, only one subscription profile is active
at a time, as the mobile device can only be used with one subscription profile.
[0017] According to a third aspect the invention provides for a mobile terminal containing
a secure element according to the second aspect of the invention.
[0018] The mobile terminal according to the present invention comprises means for communicating
with a cellular communications network, in order to receive a new subscription profile.
Preferably, the mobile terminal is implemented in form of a smart phone, a tablet
PC, a notebook, a PDA, or the like. Alternatively the mobile terminal can be a multimedia
device such as digital picture frame, audio equipment, a TV system, a set top box,
an e-book reader and so on. By way of example, the term "mobile terminal" also includes
any kind of machinery, like vending machines, vehicles, smart-meters and the like
that are configured to communicate via a cellular communications system.
[0019] According to a fourth aspect the invention provides for a subscription management
backend system configured to provide a secure element of a mobile terminal with a
subscription profile by means of the method according to the first aspect of the invention.
[0020] These and other features, characteristics, advantages, and objects of the invention
will be clear from the following detailed description of preferred embodiments, given
as a non-restrictive example, under reference to the attached drawings. The person
skilled in the art will appreciate, in particular, that the above preferred embodiments
can be combined in several ways, which will result in additional advantageous embodiments
that are explicitly supported and covered by the present invention. In particular,
the person skilled in the art will appreciate that the above described preferred embodiments
can be implemented in the context of the different aspects of the invention.
Brief description of the drawings
[0021]
- Fig. 1
- shows a schematic overview of a communications system illustrating several aspects
of the present invention; and
- Fig. 2
- shows a diagram illustrating a method for providing a subscription profile to the
secure element of a mobile terminal according to a preferred embodiment of the invention.
Detailed description of preferred embodiments
[0022] Figure 1 shows schematically the components of a communications system 10 as well
as some of the communication channels or links between the components of this system
10 that illustrate several aspects of the present invention. Although the below detailed
description will refer to a "mobile" terminal, the person skilled in the art will
appreciate that the present invention can be advantageously implemented in the context
of any kind of devices that are configured to communicate via a mobile or cellular
communications network. In other words, the attribute "mobile" used herein refers
to the ability of a terminal to communicate via a mobile or cellular communications
network, also including IP based mobile communication networks.
[0023] An exemplary mobile terminal 12 is shown in figure 1 including a secure element 20
for securely storing and processing data that uniquely identifies the secure element
20, the mobile terminal 12 and/ or its user. As indicated in figure 1, the mobile
terminal 12 preferably is a mobile phone, smart phone or a similar device. The person
skilled in the art will appreciate, however, that the mobile terminal 12 according
to the present invention can be implemented in the form of other devices as well,
such as a tablet or notebook computer, a TV system, a set top box, a vending machine,
a vehicle, a surveillance camera, a sensor device and the like.
[0024] According to preferred embodiments of the invention the secure element 20 is configured
as an eUICC or UICC with a SIM application running thereon, i.e. a secure element
that can be mounted in the mobile terminal 12 and used in cellular communications
systems for unique and secure subscriber identification as well as for the provision
of different special functions and value-added services. Alternatively, the secure
element 20 could be configured as a subscriber identity module (SIM), the SIM currently
being the most popular type of secure element. The person skilled in the art will
appreciate, however, that other types of secure elements that, depending on the underlying
generation and type of cellular communications system standard, are designated as
USIM, R-UIM, ISIM, CSIM and the like, are also encompassed by the present invention.
Moreover, the secure element 20 could be a M2M module or a Trusted Execution Environment
(TEE) implemented as part of the mobile terminal 12.
[0025] As already mentioned above, the mobile terminal 12 is configured to communicate via
the air interface (or radio link) with a cellular communications network or public
land mobile network (PLMN) 30, preferably operated by a mobile network operator (MNO)
according to the GSM standard, for using services provided by the PLMN 30, such as
communicating with other mobile terminals connected therewith. In the following, preferred
embodiments of the invention will be described in the context of a cellular communications
network according to the standards of the Global System for Mobile communication (GSM),
as specified in a number of specifications provided by ETSI. However, the person skilled
in the art will appreciate that the present invention may be advantageously applied
in connection with other cellular communications systems as well. Such systems include
third-generation cellular communications systems (3GPP), such as the Universal Mobile
Telecommunications System (UMTS), and next generation or fourth-generation mobile
networks (4G), such as Long Term Evolution (LTE), as well as other cellular communications
systems.
[0026] As is well known to the person skilled in the art, a PLMN configured according to
the GSM standard generally comprises a base station subsystem consisting of one or
more base transceiver stations that define respective cells of the PLMN and are connected
to a base station controller. Generally, the base station controller is one of several
base station controllers that communicate with a common mobile switching center (MSC).
Often, a local database called Visitor Location Register (VLR) for keeping track of
the mobile users currently located within the cells covered by a MSC (i.e. the MSC
service area) is incorporated in the MSC. The MSC provides essentially the same functionality
as a central office switch in a public-switched telephone network and is additionally
responsible for call processing, mobility management, and radio resource management.
The MSC is further in communication with a home location register (HLR), which is
the primary database of the PLMN that stores information about its mobile users required
for authentication. To this end, the HLR generally is in communication with an authentication
center (AUC). The person skilled in the art will appreciate that although the above
described components of a conventional GSM system may have different names in different
or consecutive standards for mobile communications networks, the underlying principles
used therein are substantially similar and, therefore, compatible with the present
invention.
[0027] Of the above described components of the PLMN 30 only an exemplary base transceiver
station 32 is shown in the schematic drawing of figure 1 for ease of explanation.
The PLMN 30 is at least in temporary communication with a subscription management
backend system 40 for providing the secure element 20 of the mobile terminal 12 with
a subscription profile, as will be described in more detail further below. The PLMN
30 moreover could comprise a SMS-C (Short Message Service Center) for storing, forwarding,
converting and delivering SMS messages. Such SMS messages could be used for transmitting
a subscription profile or at least parts thereof to the secure element 20 of the mobile
terminal 12.
[0028] As can be taken from the enlarged view of the secure element 20 in figure 1, the
following preferred software architecture is implemented thereon. A Java Card™ runtime
environment (JCRE) 24 is implemented on top of a native operating system (OS) 22 of
the secure element 20. Generally, the native operating system 22 and the Java Card™
runtime environment 24 are installed by the manufacturer during the manufacturing
process of the secure element 20. The Java Card™ runtime environment 24 comprises
a Java Card™ Virtual Machine (JCVM) 26 as well as at least one Java Card™ application
programming interface (API) 16'. By means of Java Card™ APIs any applets running on
the secure element 20 can execute functions that are provided by the Java Card™ Virtual
Machine 26 and the native operating system 22. Further details about this conventional
software architecture can be found, for instance, in the book "Java Card™ Technology
for Smart Cards", Zhiqun Chen, Addison-Wesley, 2000, which is fully incorporated herein
by reference.
[0029] As will be appreciated by the person skilled in the art, for implementing and running
the above described software components the secure element 20 generally will comprise
a central processing unit (CPU) for processing data as well as a memory unit for storing
data, which for the ease of illustration are not shown in figure 1. Preferably, the
CPU is configured such that at least one application can be executed on the CPU providing
for features that will be described in the context of figure 2 in more detail further
below. The application could be implemented, for instance, as a Java Applet. Preferably,
the memory unit is implemented as a non-volatile, rewritable flash memory. Preferably,
at least a portion thereof is configured to securely store secret data therein, such
as subscription credentials that are part of a subscription profile. Preferably, the
memory unit supports storage of multiple subscription profiles, for instance, in the
form of "slots" for accommodating subscription profiles, such as a subscription profile
to be provided by the subscription management backend system 40 according to the process
shown in figure 2 and described in more detail further below. The multiple subscription
profiles may be associated with one MNO or different MNOs.
[0030] Preferably, a first subscription profile can be stored in the memory unit of the
secure element 20 during the manufacturing and/or personalization process of the mobile
terminal 12 and/or its secure element 20. Especially in this preferred embodiment
it is conceivable that this first subscription profile is merely a provisional subscription
profile only providing for basic services that allow the secure element 20 and mobile
terminal 12 to communicate with the subscription management backend system 40 and
to download a more complete subscription profile providing for additional services.
As a provisional subscription profile generally provides only a limited functionality,
the user of the mobile terminal 12 generally will be enticed to change to a more complete
subscription profile providing for additional services.
[0031] Generally, a subscription profile can comprise at least parts of an operating system
of the secure element 20, one or more applications, such as a PLMN access application
containing a MNO specific authentication algorithm, files and/or data, such as subscription
credentials that allow the secure element 20 and the mobile terminal 12 to attach
to the PLMN 30, for instance an International Mobile Subscriber Identity (IMSI) for
identifying and/ or an authentication key K
i for authenticating the secure element 20.
[0032] A preferred way of operating the subscription management backend system 40, preferably
in the form of a subscription management server 40, in combination with the other
elements of the communications system 10 shown in figure 1 will now be described under
further reference to figure 2.
[0033] In step S1 of figure 2, the secure element 20 attaches to the PLMN 30 by using the
subscription profile (or one of the subscription profiles) and, in particular, the
subscriptions credentials thereof stored in the memory unit of the secure element
20. Having successfully attached to the PLMN 30, the secure element 20 requests in
step S2 of figure 2 to retrieve a new subscription profile for accessing a target
PLMN from the subscription management backend system 40. As the person skilled in
the art will appreciate, this target PLMN 30 could be the PLMN 30 or a different PLMN
operated by a different MNO. In response to this request, the subscription management
backend system 40 uploads in step S3 of figure 2 a subscription management interface
16 to the secure element 20.
[0034] After having downloaded the subscription management interface 16 from the subscription
management backend system 40 in step S3 of figure 2, the subscription management interface
16 is implemented on the secure element 20 in step S4 of figure 2. Prior to implementing
the subscription management interface 16 this step could include the additional step
of checking the integrity of the subscription management interface 16 by the secure
element 20, for instance, by calculating a checksum. The subscription management interface
16 could be implemented as an applet that together with the Java Card™ APIs 16' already
present on the secure element 20 provides for an API that allows to interact with
and process a subscription profile having a format used by the MNO of the target PLMN.
[0035] Preferably, the secure element 20 sends in step S5 of figure 2 a confirmation message
to the subscription management backend system 40 that the subscription management
interface has been implemented successfully. In response to this confirmation message,
the subscription management backend system 40 uploads the subscription data 18 in
the format provided by the MNO of the target PLMN to the secure element 20 (step S6
of figure 2).
[0036] Having receiving the subscription data in the format provided by the MNO of the target
PLMN, the secure element in step S7 of figure 2 processes this subscription data 18
using the subscription management interface 16 implemented on the secure element 20
in step S4 of figure 2. In doing so, the secure element 20 implements the target subscription
profile.
[0037] Once the target subscription profile has been successfully implemented on the secure
element 20, the secure element 20 can try to attach to the target PLMN (step S8 of
figure 2). In case of a successful attachment to the target PLMN, the secure element
20 preferably sends a confirmation message to the subscription management backend
system 40 (step S9 of figure 2).
[0038] Before or substantially concurrently with implementing the target subscription profile
on the secure element 20 the subscription management backend system 40 preferably
sends a confirmation message to the MNO of the target PLMN. In response thereto the
MNO can activate the subscription credentials of the target subscription profile in
its HLR/AUC so that the mobile terminal 12 and its secure element 20 can attach to
the target PLMN using the subscription credentials of the target subscription profile.
[0039] In light of the above detailed description the person skilled in the art will appreciate
that modifications and/or additions can be made to the methods, devices and systems
as described heretofore, which are to be considered to remain within the scope of
the present invention as defined by the appended claims. In particular, the person
skilled in the art will appreciate that the present invention is not restricted to
the number and sequence of steps shown in figure 2. For instance, steps S3 and S6
of figure 2 could be incorporated in a single step.
1. A method for providing a secure element (20) having a processor and a memory of a
mobile terminal (12) with a target subscription profile for communicating via a target
mobile network, wherein the method comprises the steps of:
providing as a first part of the target subscription profile a subscription management
interface (16) to the secure element (20);
implementing the subscription management interface (16) on the secure element (20);
and
providing as a second part of the target subscription profile subscription data (18)
in a format defined by the operator of the target mobile network to the secure element
(20),
wherein the subscription management interface (16) allows the secure element (20)
to process the subscription data (18) and to implement the target subscription profile
thereon for allowing access to the target mobile network.
2. The method of claim 1, wherein the subscription management interface (16) implements
a standardized application programming interface on the secure element (20) for processing
the subscription data (18) used by the operator of the target mobile network.
3. The method of claim 1, wherein the method comprises prior to the step of providing
as a first part of the target subscription profile a subscription management interface
(16) to the secure element (20) the additional step of attaching to a mobile network
supported by a subscription profile already present on the secure element (20).
4. The method of claim 3, wherein the subscription profile already present on the secure
element (20) is a provisioning subscription profile.
5. The method of claim 1, wherein the method comprises prior to the step of providing
as a first part of the target subscription profile a subscription management interface
(16) to the secure element (20) the additional step of requesting the target subscription
profile from a subscription management backend system (40).
6. The method of claim 1, wherein the method comprises after the step of implementing
the subscription management interface (16) on the secure element (20) the additional
step of sending a confirmation message to a subscription management backend system
(40).
7. The method of claim 1, wherein the step of implementing the subscription management
interface (16) on the secure element (20) comprises the additional step of checking
the integrity of the subscription management interface (16) by the secure element
(20).
8. The method of claim 1, wherein the method comprises after the step of providing the
subscription data (18) in a format defined by the operator of the target mobile network
to the secure element (20) the additional steps of attaching to the target mobile
network and sending a confirmation message to a subscription management backend system
(40).
9. A secure element (20) comprising a subscription profile provided to the secure element
(20) by the method according to anyone of the preceding claims.
10. The secure element (20) of claim 9, wherein the secure element (20) is configured
as a subscriber identity module (SIM) or an embedded Universal Integrated Circuit
Cards (eUICCs).
11. A mobile terminal (12) containing a secure element (20) according to claims 9 or 10.
12. A subscription management backend system (40) configured to provide a secure element
(20) of a mobile terminal (12) with a subscription profile by the method according
to anyone of claims 1 to 8.